package com.ht.common.core.utils.ip;

import java.net.InetAddress;
import java.net.UnknownHostException;
import javax.servlet.http.HttpServletRequest;

import com.ht.common.core.utils.ServletUtils;
import com.ht.common.core.utils.StringUtils;

/**
 * 获取IP方法
 *
 * @author ruoyi
 */
public class IpUtils{
        public final static String REGX_0_255 = "(25[0-5]|2[0-4]\\d|1\\d{2}|[1-9]\\d|\\d)";
        // 匹配 ip
        public final static String REGX_IP = "((" + REGX_0_255 + "\\.){3}" + REGX_0_255 + ")";
        public final static String REGX_IP_WILDCARD = "(((\\*\\.){3}\\*)|(" + REGX_0_255 + "(\\.\\*){3})|(" + REGX_0_255 + "\\." + REGX_0_255 + ")(\\.\\*){2}" + "|((" + REGX_0_255 + "\\.){3}\\*))";
        // 匹配网段
        public final static String REGX_IP_SEG = "(" + REGX_IP + "\\-" + REGX_IP + ")";

        /**
         * 获取客户端IP
         *
         * @return IP地址
         */
        public static String getIpAddr()
        {
            return getIpAddr(ServletUtils.getRequest());
        }

        /**
         * 获取客户端IP
         *
         * @param request 请求对象
         * @return IP地址
         */
        public static String getIpAddr(HttpServletRequest request)
        {
            if (request == null)
            {
                return "unknown";
            }
            String ip = request.getHeader("x-forwarded-for");
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = request.getHeader("Proxy-Client-IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = request.getHeader("X-Forwarded-For");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = request.getHeader("X-Real-IP");
            }

            if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip))
            {
                ip = request.getRemoteAddr();
            }

            return "0:0:0:0:0:0:0:1".equals(ip) ? "127.0.0.1" : getMultistageReverseProxyIp(ip);
        }

        /**
         * 检查是否为内部IP地址
         *
         * @param ip IP地址
         * @return 结果
         */
        public static boolean internalIp(String ip)
        {
            byte[] addr = textToNumericFormatV4(ip);
            return internalIp(addr) || "127.0.0.1".equals(ip);
        }

        /**
         * 检查是否为内部IP地址
         *
         * @param addr byte地址
         * @return 结果
         */
        private static boolean internalIp(byte[] addr)
        {
            if (StringUtils.isNull(addr) || addr.length < 2)
            {
                return true;
            }
            final byte b0 = addr[0];
            final byte b1 = addr[1];
            // 10.x.x.x/8
            final byte SECTION_1 = 0x0A;
            // 172.16.x.x/12
            final byte SECTION_2 = (byte) 0xAC;
            final byte SECTION_3 = (byte) 0x10;
            final byte SECTION_4 = (byte) 0x1F;
            // 192.168.x.x/16
            final byte SECTION_5 = (byte) 0xC0;
            final byte SECTION_6 = (byte) 0xA8;
            switch (b0)
            {
                case SECTION_1:
                    return true;
                case SECTION_2:
                    if (b1 >= SECTION_3 && b1 <= SECTION_4)
                    {
                        return true;
                    }
                case SECTION_5:
                    switch (b1)
                    {
                        case SECTION_6:
                            return true;
                    }
                default:
                    return false;
            }
        }

        /**
         * 将IPv4地址转换成字节
         *
         * @param text IPv4地址
         * @return byte 字节
         */
        public static byte[] textToNumericFormatV4(String text)
        {
            if (text.length() == 0)
            {
                return null;
            }

            byte[] bytes = new byte[4];
            String[] elements = text.split("\\.", -1);
            try
            {
                long l;
                int i;
                switch (elements.length)
                {
                    case 1:
                        l = Long.parseLong(elements[0]);
                        if ((l < 0L) || (l > 4294967295L))
                        {
                            return null;
                        }
                        bytes[0] = (byte) (int) (l >> 24 & 0xFF);
                        bytes[1] = (byte) (int) ((l & 0xFFFFFF) >> 16 & 0xFF);
                        bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                        bytes[3] = (byte) (int) (l & 0xFF);
                        break;
                    case 2:
                        l = Integer.parseInt(elements[0]);
                        if ((l < 0L) || (l > 255L))
                        {
                            return null;
                        }
                        bytes[0] = (byte) (int) (l & 0xFF);
                        l = Integer.parseInt(elements[1]);
                        if ((l < 0L) || (l > 16777215L))
                        {
                            return null;
                        }
                        bytes[1] = (byte) (int) (l >> 16 & 0xFF);
                        bytes[2] = (byte) (int) ((l & 0xFFFF) >> 8 & 0xFF);
                        bytes[3] = (byte) (int) (l & 0xFF);
                        break;
                    case 3:
                        for (i = 0; i < 2; ++i)
                        {
                            l = Integer.parseInt(elements[i]);
                            if ((l < 0L) || (l > 255L))
                            {
                                return null;
                            }
                            bytes[i] = (byte) (int) (l & 0xFF);
                        }
                        l = Integer.parseInt(elements[2]);
                        if ((l < 0L) || (l > 65535L))
                        {
                            return null;
                        }
                        bytes[2] = (byte) (int) (l >> 8 & 0xFF);
                        bytes[3] = (byte) (int) (l & 0xFF);
                        break;
                    case 4:
                        for (i = 0; i < 4; ++i)
                        {
                            l = Integer.parseInt(elements[i]);
                            if ((l < 0L) || (l > 255L))
                            {
                                return null;
                            }
                            bytes[i] = (byte) (int) (l & 0xFF);
                        }
                        break;
                    default:
                        return null;
                }
            }
            catch (NumberFormatException e)
            {
                return null;
            }
            return bytes;
        }

        /**
         * 获取IP地址
         *
         * @return 本地IP地址
         */
        public static String getHostIp()
        {
            try
            {
                return InetAddress.getLocalHost().getHostAddress();
            }
            catch (UnknownHostException e)
            {
            }
            return "127.0.0.1";
        }

        /**
         * 获取主机名
         *
         * @return 本地主机名
         */
        public static String getHostName()
        {
            try
            {
                return InetAddress.getLocalHost().getHostName();
            }
            catch (UnknownHostException e)
            {
            }
            return "未知";
        }

        /**
         * 从多级反向代理中获得第一个非unknown IP地址
         *
         * @param ip 获得的IP地址
         * @return 第一个非unknown IP地址
         */
        public static String getMultistageReverseProxyIp(String ip)
        {
            // 多级反向代理检测
            if (ip != null && ip.indexOf(",") > 0)
            {
                final String[] ips = ip.trim().split(",");
                for (String subIp : ips)
                {
                    if (false == isUnknown(subIp))
                    {
                        ip = subIp;
                        break;
                    }
                }
            }
            return StringUtils.substring(ip, 0, 255);
        }

        /**
         * 检测给定字符串是否为未知，多用于检测HTTP请求相关
         *
         * @param checkString 被检测的字符串
         * @return 是否未知
         */
        public static boolean isUnknown(String checkString)
        {
            return StringUtils.isBlank(checkString) || "unknown".equalsIgnoreCase(checkString);
        }

        /**
         * 是否为IP
         */
        public static boolean isIP(String ip)
        {
            return StringUtils.isNotBlank(ip) && ip.matches(REGX_IP);
        }

        /**
         * 是否为IP，或 *为间隔的通配符地址
         */
        public static boolean isIpWildCard(String ip)
        {
            return StringUtils.isNotBlank(ip) && ip.matches(REGX_IP_WILDCARD);
        }

        /**
         * 检测参数是否在ip通配符里
         */
        public static boolean ipIsInWildCardNoCheck(String ipWildCard, String ip)
        {
            String[] s1 = ipWildCard.split("\\.");
            String[] s2 = ip.split("\\.");
            boolean isMatchedSeg = true;
            for (int i = 0; i < s1.length && !s1[i].equals("*"); i++)
            {
                if (!s1[i].equals(s2[i]))
                {
                    isMatchedSeg = false;
                    break;
                }
            }
            return isMatchedSeg;
        }

        /**
         * 是否为特定格式如:“10.10.10.1-10.10.10.99”的ip段字符串
         */
        public static boolean isIPSegment(String ipSeg)
        {
            return StringUtils.isNotBlank(ipSeg) && ipSeg.matches(REGX_IP_SEG);
        }

        /**
         * 判断ip是否在指定网段中
         */
        public static boolean ipIsInNetNoCheck(String iparea, String ip)
        {
            int idx = iparea.indexOf('-');
            String[] sips = iparea.substring(0, idx).split("\\.");
            String[] sipe = iparea.substring(idx + 1).split("\\.");
            String[] sipt = ip.split("\\.");
            long ips = 0L, ipe = 0L, ipt = 0L;
            for (int i = 0; i < 4; ++i)
            {
                ips = ips << 8 | Integer.parseInt(sips[i]);
                ipe = ipe << 8 | Integer.parseInt(sipe[i]);
                ipt = ipt << 8 | Integer.parseInt(sipt[i]);
            }
            if (ips > ipe)
            {
                long t = ips;
                ips = ipe;
                ipe = t;
            }
            return ips <= ipt && ipt <= ipe;
        }

        /**
         * 校验ip是否符合过滤串规则
         *
         * @param filter 过滤IP列表,支持后缀'*'通配,支持网段如:`10.10.10.1-10.10.10.99`
         * @param ip 校验IP地址
         * @return boolean 结果
         */
        public static boolean isMatchedIp(String filter, String ip)
        {
            if (StringUtils.isEmpty(filter) || StringUtils.isEmpty(ip))
            {
                return false;
            }
            String[] ips = filter.split(";");
            for (String iStr : ips)
            {
                if (isIP(iStr) && iStr.equals(ip))
                {
                    return true;
                }
                else if (isIpWildCard(iStr) && ipIsInWildCardNoCheck(iStr, ip))
                {
                    return true;
                }
                else if (isIPSegment(iStr) && ipIsInNetNoCheck(iStr, ip))
                {
                    return true;
                }
            }
            return false;
        }
}
